Rotary Valve Lockout Apparatus

ABSTRACT

An apparatus for locking the position of the rotary valve, wherein the valve has a valve shaft adapted to have first and second opposed flatted formations. The apparatus includes first and second cam followers. The cam followers are reciprocally movable via the action of a cam assembly comprising first and second cams mounted on a rotatable cam stem. The cam followers can be simultaneously moved in opposite directions whereby engagement walls in the first and second cam followers can engage the first and second opposed flatted formations simultaneously.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Application No. 63/296,731filed Jan. 5, 2022, the disclosure of which is incorporated herein byreference for all purposes.

FIELD OF INVENTION

The present invention relates to valve-actuator combinations and, moreparticularly, to a lockout apparatus which enables users of rotaryvalves to lock the valve in a specified rotational position usually toprovide a safe operating environment for piping maintenance personnel.

BACKGROUND OF THE INVENTION

Currently, locking a rotary valve in a desired position is accomplishedby inserting a pin, typically, in the valve shaft and a speciallydesigned mounting bracket. This method requires a separate pin thatmight be chained to the bracket to prevent it being misplaced and also aperfectly aligned shaft/bracket hole combination to allow pin insertion.

SUMMARY OF THE INVENTION

In one embodiment, the apparatus of the present invention operates bypinching opposed flatted surfaces of a valve/actuator shaft.

In another embodiment, the apparatus of the present invention operatesby pinching opposed flatted surfaces on a coupler that connects thevalve shaft and actuator shafts.

In another embodiment of the present invention, the apparatus provides amethod to adjust the alignment between the pinching assembly and theflatted coupler/shaft surfaces. This is desirable because not all valvesrequire the exact same position when being locked, due either to thevalve design or to shifting valve shaft position over time such as frombracket slippage, valve torque induced shaft windup, etc.

In one embodiment, the apparatus is mounted below the actuator and abovethe valve, i.e., the apparatus is a bottom mounted lockout (BMLO).However, it can be mounted on the top side of the actuator from thevalve if the actuator shaft and engagement can provide sufficientstrength to ensure locking with full actuator torque output.

In another embodiment, there are fasteners, e.g., bolts, which connectthe valve and actuator, usually via a mounting bracket, and which passfrom the mounting bracket, through the BMLO, and into the actuator toprovide the ability for the actuator to apply the necessary torque tooperate the valve. The BMLO can have spacers to prevent crushing of theplates which form part of the BMLO, the crushing of which would preventtheir subsequent movement.

In another embodiment the BMLO comprises a stack of four plates, two ofwhich are moveable, two cams and a lever to cause rotation of the camswhich then impart opposite directional movement of the moveable plates.

In the normal position, the moveable plates provide no resistance toactuator valve rotation but when the cams are rotated 180 degrees by thelever, the moveable plates are caused to move toward one another untilthey contact the opposed flatted surfaces of the coupler/shaft. In thisposition, the cams are axially aligned with the moveable plates suchthat forces against the flatted surfaces of the plates from any appliedactuator or valve torques, are unable to result in rotational torquebeing applied to the cams. The moveable plates remain in the lockoutposition so long as the cams are not rotated by operating personnel. Theapparatus can include tag out/lock out padlocks so that operatingpersonnel are unable to cause cam rotation without proper authorization.Similarly, padlock provisions can be included to prevent unauthorizedengagement of the lockout.

In still a further embodiment, the plates, both stationary and moveable,can have markings or other indicia to provide visual indication of theirrelative positions so that operating personnel are able to quicklydetermine the state of operation of the valve. Additionally, switchesand other means of providing local and/or remote position indication canbe incorporated into the BMLO.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one embodiment of the BMLO apparatus ofthe present invention positioned below an actuator and above a valve(not shown) to which the actuator would be attached.

FIG. 2 is a perspective view of the BMLO apparatus of FIG. 1 with theactuator removed.

FIG. 3 is a perspective view of the BMLO shown in FIG. 2 but with thetop fixed plate removed and the BMLO in the unlocked position.

FIG. 4 is a perspective view of the BMLO shown in FIG. 2 with the topfixed plate and top movable plate removed.

FIG. 5 is a perspective view of the BMLO of FIG. 2 with the top fixedplate removed and the apparatus in the lock out position.

FIG. 6 is a top plan view of the BMLO shown in FIG. 5 .

FIG. 7 is similar to FIG. 6 but showing the BMLO in the unlockedposition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIG. 1 , the apparatus (BMLO) of the presentinvention shown generally as 10, is seen as positioned below an actuatorA and above a typical bracket 12 used to connect actuator A to a rotaryvalve (not shown). Turning to FIG. 2 , it can be seen that the BMLO 10of the present invention comprises four stacked plates, 14, 16, 18, and20. As shown in FIG. 2 , valve shaft or actuator shaft 22 extendsthrough registering openings in the plates 14-20. Plate 14 includesbores 15 for fasteners (not shown) to mount the apparatus 10 to theactuator. It will be appreciated that the number and position of bores15 can vary depending on the nature of the particular actuator. It is tobe understood that while the valve or actuator shaft can be formed withopposed flatted, e.g., wrench, surfaces typically a coupler 32 (see FIG.3 ) is used to connect the actuator and rotary valve shaft together, thecoupler being provided with flatted surfaces as seen hereafter. Theshaft/coupler can be square in cross-section providing two other opposedflatted surfaces or formations.

A cam stem 24 extends through registering openings in plates 14, 16, and18, and has removably attached thereto a lever 26 by which stem 24 canbe rotated 180° from the position shown in FIG. 2 until lever 26 engagesstop 28 connected to and extending upwardly from plate 14.

FIG. 3 shows the BMLO 10 with the top, fixed plate removed. As shown,movable plate 16 has an H-shaped aperture 30 through which shaft 22extends, shaft 22 being connected to a coupler 32. H-shaped aperture 30is partially defined by an engagement wall section 31. Plate 16 is alsoprovided with slots 34 and 36 located on opposite sides of H-shapedaperture 30. Guides/spacer posts 40 extend through slots 34 and 36.Plate 16 also has a second aperture 42 in which is disposed a first camplate 60 which is fixedly attached to stem 24 and which, as can be seen,is generally coplanar with plate 16.

Turning now to FIG. 4 , the BMLO 10 of the present invention is shownwith the top fixed and movable plates (14, 16) removed. Bottom movableplate 18 has an H-shaped aperture 50 similar to aperture 30 but rotated180° relative to aperture 30. H-shaped aperture 50 is partially formedby an engagement wall 33. Plate 18 also has slots 52 and 54 as well asan aperture 56 in which is positioned a second cam plate 58, cam plate58 being substantially co-planar with movable plate 18. As can be seenfrom FIG. 4 , cam plates 60 and 58 can be of various shapes but as shownin one embodiment are generally circular and are eccentrically mountedon stem 24, cam plates 58 and 60, when mounted, being axially displacedand laterally positioned 180° from one another. FIG. 4 also shows ingreater detail, the flatted surfaces of coupler 32. In this regard,coupler 32 has a first flatted surface 70 and a second flatted surface72, flatted surface 70 being provided with spaced engagement positionscrews 70A and 70B which can be independently adjusted. In a similarfashion, flatted surfaces 72 has spaced engagement position screws, onlyone of which 72A is shown. Engagement screws 70A and 70B are generallycoplanar with top movable plate 16 while engagement screws 72A and theother engagement screw not shown, are generally coplanar with bottommovable plate 18. Thus, it will be appreciated that linear movement ofplate 16 in response to the action of cam plate 60 will drive engagementwall section 31 into engagement with screws 70A and 70B whilecorresponding movement of cam plate 58 against bottom movable plate 18will drive engagement wall section 33 into engagement with screws 72Aand other screw (not shown) extending from flatted surface 72.Accordingly, by proper adjustment of the screws 70A, 70B, 72A, and 72B(not shown), engagement wall section 31 can be brought into engagementwith engagement screws 70A and 70B and engagement wall section 33 can bebrought into simultaneously engagement with adjustment screws 72A. Itwill be understood that the engagement with adjustment screws by thewall sections is effectively operative engagement with the flattedsurfaces of coupler 32. It will be appreciated that adjustment screws70A and 72A are optional, since the flatted surfaces per se can be thesurfaces engaged by the movable plates. However, the adjustment screwsafford fine tuning. Basically, wall sections 31 and 33 can be consideredfollower surfaces in the sense that moveable plates 16 and 18 are camfollowers.

It will thus be appreciated that when lever 26 is moved 180° from theposition shown in FIG. 4 to the position shown in FIG. 5 , the camplates 60 and 58 being in driving engagement with movable plates 16 and18, respectively, will result in the opposite movement of movable plates16 and 18 in the direction of arrows A and B, respectively. Furthermore,the movement of the plates 16 and 18 will be substantially simultaneoussuch that the engagement wall sections 31 and 33 will engage theadjustment screws on coupler 32 at substantially the same time.

This engagement in the lockout position as depicted in FIG. 6 shows themoveable plates 16 and 18 axially aligned with the cam shaft axis Xthereby preventing rotation of the cam axially through forces whichmight act on the movable plates 16 and 18.

Turning to FIG. 7 , the BMLO of the present invention is shown in theunlocked position and in this regard it can be seen that engagement wallsections 31 and 33 are no longer engaged with the adjustment screws onthe coupler 32.

As can be seem from the above the BMLO of the present invention has thefollowing benefits:

-   -   an improved method to lock out a valve for the safety of        operating personnel.    -   two plates that are caused to move via lever (or wrench)        operated cams which pinch a flatted portion of a coupler,        actuator shaft or valve shaft to prevent rotation.    -   optional adjustability of the locking position.    -   cam axis positions are aligned with the axis of the moveable        plates so that forces applied to the plates are not able to        cause rotation of the cams nor the subsequent unintended        disengagement of the BMLO.    -   a lever to cause rotation of the stem to which the cams are        mounted, but which may be removed to allow operation via a        common wrench.    -   an apparatus enabling padlocking of the moveable plates in        either the engaged or disengaged positions to prevent        unauthorized operation.    -   has provisions for optional markings to clearly identify the        state of the BMLO. An ability exists to ‘hide’ markings as the        moveable plates change positions so that only the appropriate        markings are visible in both the engaged and disengaged        positions.

Although specific embodiments of the invention have been describedherein in some detail, this has been done solely for the purposes ofexplaining the various aspects of the invention, and is not intended tolimit the scope of the invention as defined in the claims which follow.Those skilled in the art will understand that the embodiment shown anddescribed is exemplary, and various other substitutions, alterations andmodifications, including but not limited to those design alternativesspecifically discussed herein, may be made in the practice of theinvention without departing from its scope.

What is claimed is:
 1. An apparatus for locking the position of a rotaryvalve having a valve shaft adapted to have first and second opposed,flatted formations, comprising: a plate stack, said plate stackcomprising: first and second fixed plates having first and secondregistering openings, respectively; a first movable plate having firstand second spaced apertures, said first aperture being partially definedby a first wall section; a second movable plate having third and fourthspaced apertures, said first and third apertures being in at leastpartial register with said second and fourth apertures, respectively,said third aperture being at least partially defined by a second wallsection, said first aperture and said third aperture having portionswhich are in register to form a passage for said shaft; a cam assemblymounted in said plate stack, said cam assembly comprising: a stemextending through said first and second movable plates and said firstfixed plate; first and second cams mounted in axially spacedrelationship on said stem, said first cam being drivingly engageablewith said first movable plate, said second cam being drivinglyengageable with said second movable plate; whereby rotation of said stemcauses said first and second cams to engage said first and secondmovable plates, respectively, and said first and second wall sectionsinto operative engagement with said first and second flatted formations,respectively.
 2. An apparatus for locking the position of a rotary valvehaving a valve shaft adapted to have first and second opposed, flattedformations, comprising: a plate stack, said plate stack comprising: afirst cam follower having first and second spaced apertures, said firstaperture being partially defined by a first wall section; a second camfollower having third and fourth spaced apertures, said first and thirdapertures being in at least partial register with said second and fourthapertures, respectively, said third aperture being at least partiallydefined by a second wall section, said first aperture and said thirdaperture having portions which are in register to form a passage forsaid shaft; a cam assembly mounted in operative engageability with firstand second cam followers, said cam assembly comprising: a stem extendingthrough said first and second movable plates; first and second camsmounted in axially spaced relationship on said stem, said first cambeing drivingly engageable with said first cam follower, said second cambeing drivingly engageable with said second cam follower; wherebyrotation of said stem causes said first and second cams to engage saidfirst and second movable plates, respectively, and said first and secondwall sections into operative engagement with said first and secondflatted formations, respectively.